Edward Byram and Talbot Chubb

Byram:

I wondered why the National Geographic?

Chubb:

Because he’s the best we could get.

Hirsch:

Well, as I told you on the phone, I’m doing research with Homer Newell working on the history of x-ray astronomy, and obviously, coming down to the people that are directly involved in it, we’ve been talking to a whole bunch of people all over the country. It’s been quite something.

Byram:

Have you been to Berkeley?

Hirsh:

I haven’t been there, no.

Chubb:

[???] probably will never recover from.

Hirsh:

Why is that?

Chubb:

Because he’s a character.

Byram:

He used to be.

Chubb:

I think he probably still is.

Hirsh:

In what regard? How is he a character?

Chubb:

Well, you’ll find out.

Hirsh:

Cooperative? Uncooperative?

Chubb:

He’s very enthusiastic.

Hirsh:

I don’t think I’ll be able to get out there, but maybe we’ll phone him and see what happens. Well, let me ask you first just about NLB in general. How it’s set up. I really don’t know much about the organization, how it runs. [???] you can tell me something about it.

Chubb:

How it originated?

Hirsh:

Okay.

Chubb:

I don’t know; there is a history of NRL. It was founded by a committee. Thomas Edison was maybe the chairman of that committee in 1924 or something like that.

Chubb:

Thomas Edison made a recommendation that there should be a laboratory working for the navy that would contain competent scientist who could advise the navy on many things, and this recommendation of his was based upon what he felt or judged to be a lack of a sort of forefront [???] of technical guidance within the navy that existed during World War I. I think it was this recommendation that led to the establishment of NRL. I’m not a historian. There are several, as you say — at least three — histories that are available on it.

Hirsh:

Well, how did these [???] get established here?

Byram:

Mainly by Dr. Hubbard. Well, (Rocket) Walkathon Life — I don’t know how they originated. They got into the rocket technology and from that I guess it expanded into doing science.

Chubb:

I think NRL has always had a very strong interest in the ionosphere, and wasn’t it Dr. Taylor who did some of the original ionospheric researches in conjunction with the Carnegie Institute. And of course there the problem and the interest arose because of the navy communications problems and the fact that it’s basically a world-wide service depends on having world-wide communications. And Dr. Page — I don’t know whether he ever received the credit for the heterodyne receiver or whether...

Byram:

No, that was somebody on the West Coast.

Chubb:

I think he invented the heterodyne independently and maybe number 2, though; I’m not quite sure what the situation is but NRL really was right in the forefront of radio communications in the ‘20s, so there was that long tradition and then Holbert had his interest in the ionosphere and the air glow. He was truly an outstanding scientist who probably has really not received the recognition that he deserved. Remember his papers on the twilight...

Byram:

Yes.

Chubb:

The color of the twilight sky and the analysis of the absorption when effect of ozone absorption when the sun’s rays came too long and slanted paths in the atmosphere.

Hirsh:

And when did the sounding rocket programs begin?

Byram:

Wasn’t that 1946 or 1945?

Chubb:

They, of course, aroused [???] from …

Byram:

Yes, Dr. Newell organized that thing.

Hirsh:

No, I think Krause.

Byram:

Yes, that’s right.

Hirsh:

I think Ernie Krause was the... That predates me.

Byram:

Me, too.

Chubb:

I think the fact that these German rockets were captured and taken to White Sand was a resource that was recognized by Krause and maybe others here, but Krause was really the person who really took advantage of the opportunity. I think what caused the organization [???]. Actually the optics division under Holbert was putting on experiments just about as early as any of the rocket [???] I think. But in the early days research was carried out here in two divisions: the optics division and the rockets sound division. And the first experiments in the optics area were Dr. Tousey’s spectrometers, I believe, that were put on the payoff sections of the B-2 rockets. I’m sure you have the famous picture of the opening up of the spectrum of the sun as recorded from the B-2 that showed for the first time the extension of the spectrum over the ozone region, which led to probably as good values of ozone versus altitude that exists even today and Dr. Friedman at that time was not in Holbert’s division, right? He was in metallurgy when he first came.

Byram:

When he first came here. I don’t remember when he came. When I came in 1947 Dr. Friedman’s branch was well set up, and I thought he had been there for a couple of years at least. And Dr. Friedman started off in x-ray spectroscopy and in the metallurgy division using [???] to give quick analysis of metallurgical samples [???] active.

Chubb:

In fact, a good portion of the national technology on X-ray fluorescent spectroscopy really came out of his work and his cooperation with North American [???], who was just getting into the business and picked up a lot of the techniques developed by Friedman here at NRL.

Byram:

He came to the optics division because the optics division was working on the problem of quartz, because there was a bottleneck of quartz crystals for radio. So Dr. Friedman set up a spectroscopic x-ray scheme to examine quartz and determine the crystal orientation.

Chubb:

This had an impact on World War II in getting crystals available, [???] that real bottleneck - crystal controlled radios.

Hirsh:

So it seems like everyone...

Chubb:

In connection with that he developed Geiger tube (?) detectors, x-ray detectors; and again the bulk of the end window (?) mica tubes — mica and window Geiger counters, the Halogen (?) counters — really came out of his work here. Now, there are old German patents on Halogen (?) counters, but nothing ever came of those. But directly from his work were these which were used in the x-ray of fluorescence analysis and also these bag crystal orientations came. These mica windows tubes became almost universally used, and they were adapted after the war as the main detector used for monitoring low level radioactive radiations — the Radical instruments. And the PR 27 was the Geiger counter radiation monitoring equipment which was adapted by BOD, and [???] worked basically as a consultant to the Naval Bureau of Ships at that time that was responsible for this radiation detection equipment. And the thing that was very important about the Halogen tubes is that they didn’t go bad even if they were exposed to enormous quantities of radiation. They were basically the first permanent Geiger counters. And it really was from these detectors that came out of the x-ray astronomy business — I mean the x-ray analysis business — that really got Friedman and the rest of us into the rocket program, because these detectors turned out to have... Well, of course, they were useful as x-ray detectors, but much of the early work was almost as much directed toward the ultra-violet, and they also had sensitivity in the far ultra-violet but not in the visible and near ultra-violet ,and they led to the first really clear measurements of [???] radiations, for example, from the sun. But it really was through the sensor band that the optics — well, Friedman’s part of the optic division — got into the rocket program, and Krause came in through the spectroscopic end using photographic film as the primary recording.

Hirsh:

So it seems that people got into this through the back door.

Chubb:

Well, there was an opportunity there and the detectors were there and so packages were put aboard. I don’t know whether it was the back door. It was just here was this new opportunity, and the rocket sound division was concentrating on doing their work on the first measurements of pressure, density, electron density, defining the structure of the atmosphere. And the optics division did the radiation work.

Byram:

My first experiment was on B 2 49.

Hirsh:

And what kind of experiment was that?

Byram:

It had Geiger tubes spanning the whole spectrum from very nearly the physical all the way down to x-ray, and every one of the detectors not only detected radiation. They all went into saturation. There was tremendously more radiation in that part of the spectrum than anybody ever expected.

Hirsh:

When did that....?

Byram:

1949, 10:30 a.m., September 29.

Hirsh:

And what were the Geiger counters picking up?

Byram:

X-rays from the sun, ultra-violet from the sun.

Chubb:

And the responses were very clear because the rocket rose and you saw these signals only when the detectors were looking at the sun.

Byram:

And the detectors showed at which point the atmosphere became transparent to these radiations. That was the important part of it.

Hirsh:

How far down on the spectrum do these Geiger counters detect radiation?

Byram:

Oh, right down to 1/8 and that low. I guess we better say it’s six (?) rather than eight. (?)

Hirsh:

But definitely down into soft x-ray.

Byram:

Yes and all the way up to... around 2000.

Chubb:

The hard part to detect in those days was to detect long-wave x-rays, not short-wave x-rays. You have to use thinner windows as you go to longer wavelength x-rays, and these were all window counters, weren’t they?

Byram:

Yes, I think, so.

Chubb:

There’s a confusing measurement on x-rays in flat those early days that we have never felt was valid based upon the use of a piece of beryllium and a piece of film. This film pack was flown, but since the film was developed and showed some exposure but since the film was also exposable or affected by pressure and heating, that by itself was sort of a suspect measurement. But in addition the thickness of the beryllium was such that our present knowledge of x-rays are that really no solar x-rays could have gotten through in measurable intensities into film. So we never felt that was a valid first measurement of solar x-rays, though it’s often listed in the old literature as such. The paper was never really published until after the Friedman-Byram experiment with x-ray counters that clearly showed there were x-rays from the sun. So we always have felt that was a little bit… [???] the history a little bit.

Byram:

I tried to expose a piece of the same kind of film. It was a similar piece of beryllium. I wasn’t able to get anything through it with a little x-ray tube.

Chubb:

Of course, there always was the possibility that an enormous flare (?) occurred. But even that 30 mill measurement... Wasn’t there a 30 mill measurement?

Byram:

I don’t remember. It was 10 I think at 130. I think the 30 mill even

Chubb:

I don’t remember the details.

Byram:

That was back [???] He was [???]

Chubb:

Of course, we were rival groups within NRL.

Hirsh:

What group was Turner in?

Chubb:

He was with the rocket sound equipment.

Hirsh:

Right. And you were then…

Chubb:

We were in optics, in Colbert’s division.

Hirsh:

There was competition, but there wasn’t any antagonism or anything like that.

Byram:

Not really, no. We were good friends with most of the people.

Chubb:

And actually all our polemetry, for example, was snagged by people in that general division at NRL.

Byram:

Yes we worked with them.

Chubb:

Van Nazer (?) and John Menqel, whom you know probably one of them became very prominent, and Goddard and one of them eventually set up the spacer or mini-track locating system for satellites and communication systems. I think they’re both retired now.

Hirsh:

Were there any reports about this 1949 flight that were published?

Byram:

Yes. Chubb can probably find a reprint and if he can’t, I can.

Chubb:

I only have one copy left I think.

Byram:

I’ve got another copy.

Chubb:

We can make a xerox out of it.

Byram:

All right.

Hirsh:

Who were the people involved at this point?

Byram:

Sam Litchman and Dr. Friedman and myself, plus a couple three technicians — Joe Nemeseck (?), Bill Nichols and Dick Arnold.

Hirsh:

Was this actually the beginning then of x-ray astronomy you might say?

Byram:

That’s what we think; that’s what I think.

Hirsh:

What was Tousey doing? He was using film?

Byram:

He was using film, and he didn’t get as far into Ultraviolet as we did with this V-2. The V-2 was the first time that line alpha was determined, determined to be a large component of the Ultra-violet solar spectrum. It was also the fact that we determined which radiations caused the various layers of the ionosphere. The x-rays were responsible for the “B” layer. (I can find a copy downstairs.) And the alpha was responsible for the “D” layer. And from this same data was determined what caused radio fadeout, which were really caused by x-rays and not line alpha [???] affected the x “D” layer. During the solar flare hard x-rays are generated compared to the normal spectrum of the sun. That may have come from [???].

Chubb:

(off mike) Yes, you see, Burnett (?) claimed x-ray intensities below 4 amplitudes to 30 mills of beryllium in this [???]. For some reason or other I don’t have [???].

Byram:

I’ll go down and hunt, because I save samples of all those old papers.

Chubb:

Well, I ought to have a copy of that. It’s ridiculous.

Hirsh:

So when was an actual concerted effort begun to look at x-rays from the sun or other objects ?

Byram:

Well, in 1949.

Chubb:

It’s been continuous from then on.

Byram:

We had two B-2’s after B-2’s (V-2’s?). Both of those blew up [???]. And that was about the time you started.

Chubb:

My first trip to White Sand was on a B-2 flight. It blew up with a great ball of fire. I was out at “C” station looking through a telescope. But anyhow that Viking experiment with 21 different counters or something like that…

Byram:

No, it was more than that.

Chubb:

That was wild.

Byram:

There was something like 50 detectors on that.

Hirsh:

Also on a B-2?

Chubb:

No, that was Viking, a Viking 9, wasn’t it, or a Viking 8?

Byram:

A Viking 9. Viking 8 took off a week ahead of that.

Hirsh:

When was that?

Chubb:

Viking 8 was very spectacular. It took off during a static firing test and started vibrating and the metal that held it to the ground broke away and the rocket took off. I wasn’t out there. You were out there. And I was scheduled to go. I was supposed to go out to the airport, and I got a call from you and the rocket had already closed (?).

Hirsh:

This was a week before schedule?

Byram:

Yes.

Chubb:

See, they test fired all the Viking engines before they actually launched the rocket. Of course, all that is written up in Rosen’s book on the Viking story, which you probably read.

Hirsh:

No, I haven’t.

Chubb:

I recommend that because it’s a good book.

Hirsh:

Were you able to get any data?

Byram:

No.

Chubb:

The rocket just went up a few feet.

Byram:

It went up more than that. It landed five miles away from the [???]. It got up more than two miles high.

Hirsh:

And when was that?

Byram:

I don’t remember. I think it was ‘53, something like that.

Hirsh:

So in between... Well, in ‘49 you say was the first time you detected solar x-rays.

Byram:

Yes, the data reduction took a long time. I imagine it was two years before the paper was published.

Chubb:

There was a paper in ‘53, but I’m sure it wasn’t the original paper. It was based upon...

Byram:

We had some [???] too.

Chubb:

This was a paper on solar x-rays and e.v. (?) ionization. I’m a co-author on this paper, but I really had nothing to do with the V-2 (B-2?) ‘49 work, so I don’t know how I became a co-author on it. Oh, but it talks about Viking 9. December, ‘52 was Viking 9. So this really describes the Viking 9 results, of which we got very little. We did have some with mica cellulose windows there detected at [???] per square centimeter per second. Not too far off really.

Byram:

Viking 9 was supposed to have a controlled spin, but that controlled spin failed and the spin jet stayed on, so we (they?) could get more expansion. It went so fast finally they blew the vacuum tubes out and [???] telemeter (?) or something like that.

Hirsh:

It seems like you had a little trouble in those days with rockets. Would the [???]

Chubb:

That came later.

Byram:

No, we had aerobes before Geiger counters.

Chubb:

This is the key paper. I’ll give you this. The key paper is Friedman, Lichtman and Byram. That came out in 1951.

Byram:

It was shortly after the second B-2 paper that we started having aerobes.

Chubb:

But this itself describes a little bit of the early history which is probably more accurate than I would remember it.

Byram:

I think it was shortly after the last of the V-2’s that we started with aerobes. 1951, I think.

Chubb:

It was after the Viking.

Byram:

I remember going out there with something like 300 detectors to fill 50 spaces in the Viking Geiger tubes. These were not permanent [???], and they had a tendency to not last very long. Every day we had to test all these 300 detectors to see how they were holding up. In those days when we went out on a field trip we would go out maybe six weeks before firing.

Hirsh:

How high did these rockets go?

Byram:

The v-2-49 went 140 miles. That was a very successful flight.

Chubb:

You’re right. Aero-B (?) 9 was January 5th, 1952, Aero-B-10…

Byram:

They were all fired the same...

Chubb:

No, it was May 1st.

Byram:

That’s right. It was May 1st, I guess.

Chubb:

Aero-B 14 was 8, 9 pounds and 14, 15 and 16, and Viking 9 wasn’t until ‘53. So you’re right, Aero-B’s succeeded the Viking.

Byram:

And 34, 35 and 36 — that was after the Viking.

Chubb:

This is my next to the last copy of this. Maybe we should xerox it.

Hirsh:

Can I ask you for a little description of your backgrounds?

Byram:

Well, I had a degree in electrical engineering from the University of Toledo. I never really became an electrical engineer.

Chubb:

You have two engineering degrees. [???] Mechanical?

Byram:

Yes, I took all the courses in mechanical, and I’m really a frustrated mechanical engineer.

Hirsh:

And when did you start to do...?

Byram:

Well, I was in the army for three years for a year and a half and then I came here in the fall of ’47.

Hirsh:

And you’ve been here ever since.

Byram:

I worked for Dr. Friedman.

Hirsh:

And now what about your background? (A few phrases citing numbers that don’t seem connected to the interview)

Chubb:

Well, I was sort of a newcomer to this business since Byram, Lichtman, Nichols and Nemesack (?) and Friedman were all working together when I joined the group.

Byram:

And Dick Arnold.

Chubb:

That’s right, Dick Arnold. I forgot that. But I came here about 1950 I think it was, and I sort of did my research work at North Carolina in electrical discharges, so I just put it into the Geiger counter program at that time and really worked with E.V. Geiger counters for I guess ten or 15 years.

Hirsh:

I ask because I’m interested in seeing who got involved in space science and X-ray astronomy. It seems to me that very few astronomers got involved.

Byram:

There were no real astronomers that I would know until after NASA was born. Starting about 1956 we did have some... No, they were not.... That’s right they were...

Chubb:

Irene Dulles was the first one I met.

Byram:

Yes, I think you’re right. She was in the ultra-violet, not actually in…

Hirsh:

Why do you think this was so? That there were so few astronomers involved?

Byram:

I have my own opinion, but I do not want to publicize it.

Hirsh:

Well, we could turn off the tape recorder...

Chubb:

Early rocket measurements in the x-ray region and the various intensities that occurred, that were found in different spectral ranges, and it was put together by Kreplin who really continued in this work since he came to NPL, except for a short period. He came here as a summer student and then he worked a while, and then he went up to Carlisle, Pennsylvania and worked for a sulfide manufacturer, and he decided the navy was better, and so he came back here and he’s been working here ever since.

Byram:

I don’t remember when he came, but it was a good long time ago. It was a long time ago. I know Lichtman was there still. Did he come before you or after you?

Chubb:

I think he was after me, Lichtman was after me.

Byram:

But not long after. I remember his going out on field trips with the Aero-B’s and helping check all those Geiger counters.

Hirsh:

So it seems from this there was a pretty big effort to examine solar x-rays.

Byram:

Well, there were not many people involved, but those people were certainly pursuing actively.

Hirsh:

What did you hope to learn from these rocket flights?

Chubb:

Well, we wanted initially to find out how the ionosphere was created and why it changed with the sun spot cycle. And we also wanted to find out what was going on in the sun.

Byram:

One of the things that got us started, in addition to Dr. Holbert, was the report from the radio astronomers that there was a very high coronal temperature.

Chubb:

Then there was also… We were also interested in the atmosphere because we could provide independent information about the atmosphere — in fact, some information that was not obtainable with the pressure gauges and direct measuring instruments that we used in rocket firing. For example, we were able to measure the association (dissociation???) of oxygen in the upper atmosphere by measuring really the absorption of the molecular component and we would get a partial pressure of molecular oxygen at a [???] altitude and deduce from that the photon and perhaps we found that the mixing was carrying more [???] oxygen to much higher altitudes than some of the early theories predicted. And we also got independent measurements of the pressure based upon the altitude at which the x-rays were absorbed. And these measurements weren’t really I don’t think too well accepted at the time because they tended to be: somewhat lower pressures than the pressure gauges were indicating, but I think they’ve stood the test of time pretty well. So we were also interested in the atmosphere in that respect. But solar flare was a problem that came along and gave radio fadeouts. And, as you know, in those early days there was a big controversy as to whether x-rays or Ultra-violet was responsible for this phenomenon which basically blacks out radio communications from the [???] of the earth. And we wanted to find that out. But a lot of it was just a question wanting to really find out how the sun can produce these x-rays and what the nature of the emission was. Our tools were fairly crude in those days. We really [???] a lot more today. But I mean the early ideas weren’t all that far off, I mean we were thinking in terms of high-temperature gases, and it appears that almost… possible all, I won’t say all, but almost all of the x-ray emissions from the sun is just emissions from very hot pockets of gas.

Hirsh:

Was there any consideration of non-solar x-rays at the time?

Chubb:

I don’t think personally that there was... There was an interest in looking at all parts of the spectrum to see what was there. There was really a feeling of exploration which was proceeding with increased sensitivity as our techniques became capable of providing that increased sensitivity. The first work looking out at the sources other than the sun was really concentrated in the UV where we had a real expectation of finding things, and there were a few x-ray detectors flown around just because, you know, it was good to look, but they didn’t have the kind of areas that really led eventually to success. I’d say that we were flying (?) maybe one x-ray detector to 10 U.V.’s sort of in those early studies. When were the first studies…?

Byram:

UD 25 in 1955

Chubb:

Right, [???] UD 25 was the first non-solar experiments of our group, and I think that was the UD, wasn’t it?

Hirsh:

Who was that with?

Byram:

Kaperian (?).

Hirsh:

This was looking at non-solar ultra-violets?

Byram:

Right, it was our first night flight.

Chubb:

It was our first night flight.

Hirsh:

And what expectations did you have for looking at ultra-violet?

Chubb:

There wasn’t so much expectation. Well... There was a lot of it just seeing what you could see in those days, but there were actually hot stars that had the possibility of… [???] Byram, Chubb, Friedman and Kaperian.

Byram:

I don’t know whether they anticipated [???] alpha from the sun or not.

Chubb:

We were just a file [???] experiment on that one, weren’t we?

Byram:

I think we were. [???] halo looked like. It was a 10-inch aero-b extension.

Chubb:

We were just a file (flier?) on that first experiment. It was a meteor or [???] something like that.

Byram:

Yes.

Chubb:

It was a [???] bird (?) experiment. And we only had two detectors in that.

Byram:

Yes, that’s right. I thought there were more, but that’s right. We had a small hypodermic needle calorimeter.

Chubb:

No, no, we didn’t

Byram:

We had a calorimeter.

Chubb:

We had that kind of a calorimeter.

Byram:

Oh, that’s right. We took the tubes out. We used the same housing. I guess it was a later experiment that had…

Chubb:

A later one, the nebular glow one — quote unquote. But this was the experiment that showed the first star emissions outside the visible, and it also was the experiment that discovered the Lyman alpha glow, which was tremendously unexpected and saturated the counters by more than a factor of 10, and there were lots of arguments as to what the nature of this glow was. A lot of the arguments we were associated with were really kind of stupid, I guess. Well, no, they really weren’t that stupid. They were associated with hydrogen being collected by the sun, I believe, and as a matter of fact there is a component of the Lyman alpha glow that is due to interstellar hydrogen passing through the solar system. So what you see from earth now is completely massed by the hydrogen that’s escaping from the earth. But to get out on the moon you see the very glow that was originally postulated to explain these early results. And here the early star signals were really Milky Way type signals.

Byram:

Well, the columniation was kind of crude.

Chubb:

Was kind of crude.

Hirsh:

Those were the altitudes.

Chubb:

Those are the altitudes and this is the spectrum of the counter. So the rockets didn’t get very high either in those days. This ultraviolet is probably substantially attenuated at those altitudes, but those signals were all when the detectors were looking at the Milky Way and [???].

Hirsh:

So did you know what the sources were from this or did you…

Chubb:

No, we knew they were from the Milky Way. We just didn’t have them identified to particular stars I don’t think in that first flight. We had just a small file on an experiment. We didn’t have the full type of attitude solutions that we had when we could instrument a full rocket [???] small altitudes to see the visible stars and make (?)ometers to get our first cut of the aspect (?) and the multipliers to track down the precise aspect solution. But this rather quickly led to the second approach.

Hirsh:

Can I take the reference?

Chubb:

I’ll get it here.

Hirsh:

You said that there were some x-ray detectors on a couple of these.

Byram:

You better talk to him about them.

Chubb:

(talking off mike)

Byram:

His memory is a lot better than mine in some cases. In some cases it’s not. And I didn’t remember correctly what was in that aero-B 25, and I can’t remember the [???]

Chubb:

This is from a book called The [???] Space. (talking off mike) [???] was the editor of that.

Byram:

I’ve forgotten.

Chubb:

The Air Force Cambridge Research Lab. Delcon. Something like that.

Byram:

Velikowsky. War of the Worlds or something.

Hirsh:

That’s Velikowsky.

Byram:

Velikowsky.

Chubb:

Well, you should look at this early book, Space. [???] Why don’t you put…

Hirsh:

Okay.

Chubb:

…editor. I don’t think I’ve seen that book around here for years.

Byram:

I’ve seen a copy lately but I can’t remember whether I had it at home or downstairs. It seems to me I must have it at home. That was burnt by the sun Dr. Chubb says. I can’t believe it.

Hirsh:

(inaudible)

Byram:

The sun’s rays were focused.

Hirsh:

Oh, so it just melted it down.

Chubb:

Wait a minute, Lee.... (pause in recording) [???] at a meeting in Moscow. So this sort of followed that first (pause)

Byram:

1 can’t remember what happened between that Aero-B 25 and Aero-B 40. There was an Aero-B in there, but I’ve forgotten what...

Chubb:

Now, the first Lyman alpha map which Kaperian did, which was a very nice piece of work — let me see if it says what Aero-B that was; Aero-B 31, March 28, l957. You see, the first thing that this intense force of hydrogen radiation, which was discovered on that first nighttime flight a... I mean it was clear that that was where the excitement was. This was the most energetic… There was more energy in that wavelength coming in at night than all the other air glow lines that exist in the night sky spectrum. So the first priority really on the next night-time flight was really to find out…

Hirsh:

And that was done with Aero-B 31?

Chubb:

Aero-B 31.

Hirsh:

So it was a night-time flight.

Chubb:

Right, I believe so.

Byram:

Yes, I do too.

Chubb:

And whether there was any x-ray stuff put on there, I don’t remember.

Byram:

I don’t remember any.

Hirsh:

And you say there were a couple of x-ray detectors on these rocket shots, too?

Chubb:

I don’t remember whether there was on that one.

Hirsh:

On which one?

Chubb:

Aero-B 31. There wasn’t on that one which had the two detectors. I might conceivably have an old notebook on 31.

Hirsh:

When I talked to Dr. Kaperian he said that there was I think one detector on…

Chubb:

On Aero-B 31? I think he really was the dominant person on Aero-B 31.

Byram:

Yes, he shoved everybody else aside. He didn’t want anybody else around.

Hirsh:

Oh, Yes. I asked if he had any notebooks on that and he said he had lent them to someone — he doesn’t know who — and he hasn’t been able to get them back.

Byram:

They’re not around... I’ve never seen any of his notebooks. So I’m sure they’re not here.

Hirsh:

I hope they’re not lost.

Byram:

I’m sure they are, but I don’t think it’s that important.

Chubb:

We haven’t been all that interested in documenting the history, you know, because things get so crowded with old papers and stuff. But it was very exciting here — I’ll tell you that. These were a lot of fun, running these rockets, going out on these rockets, because every time you’d see something. The first thing was you didn’t know whether the rocket was going to work.

Byram:

We had a long string of successes, though except for those two bad B-2’s. The 8, 9 and 10, as far as rocket performance went, they were all perfect; 13, 14, and 15 were the same; 34, 35 and 36 were the same. Aero-B25 worked the same; Aero-B 31 was the same. And then I got in a fight over Aero-B 40 and 41. We just had a file (?) on.

Chubb:

But during that period our big effort was still on the sun and the solar flares and the eclipse program. The big question we were trying to answer was this question as to whether… We were pretty sure the x-rays were responsible for the effect on the earth, but we didn’t have it absolutely nailed down; and in fact it wasn’t completely nailed down until this SR-1 satellite, which was the first of the astronomical observatory, because there was always the question: did you miss the first part of the flare on the rocket ship when the real ultraviolet burst created all the low-level ionization. At the same time we were sort of beginning to do work with these small rockets in addition to the Aero-Bs.

Hirsh:

Which rockets were those?

Chubb:

Well, we started off with the balloon launched beacon rocket. Kaperian again started us off on the small rockets Rocket on a sun expedition with the rocket sun people off the coast of Greenland. And Les Meredith I think was involved in this and John Nagle I think from... I can’t remember where he was, I could he wrong about exactly who was there, but there was a group of people. And then our objective was to fire a rocket during a flare, and so we started off on the balloon launched beacon rocket in the Pacific. We had an expedition in 1956, you see, which I guess was right in the time frame, and we would fill these balloons and they’d carry the rockets in the morning, and then the winds would catch the rockets and the ship would go tracing… This was all done from a… what kind of…?

Byram:

LSD.

Chubb:

LSD, landing ship dock, with a decking over the big hole in the ship to land helicopters and also in this case to provide our platform balloon for a balloon launching. And then the balloon would move faster than the ship could move, and we’d go chasing the ship, chasing the balloon; and if it started getting out of our range, then we’d have to fire the rocket prematurely. And in one of these balloons launching rockets we did manage to fire successfully a rocket during a flare. That wasn’t when you were…

Byram:

No, I wasn’t in on those expeditions.

Chubb:

But that’s right; we got the word that the flare from Hampton (?) at Crimack (?) I think it was, the flare was in progress.

Byram:

Yes, I didn’t start going to Mount Wilson until after that.

Chubb:

Yes, that was in the next year or two when we had the… Then we switched from the balloon launched rocket to [???] boosted rockets. The first of those was the Dan, the [???] boosted beacon flow. Now, this Nike boosted technique was developed by the University of Michigan, and Les Jones I think was involved in that, and we picked it up from them and then we switched to the Asp rocket, which was a higher performance rocket than the Beacon, but it was the same physical size. And we used those from San Nicholas Island in ’57. I guess it was and we took them out on a ship during the eclipse of 1958 and showed that the x-rays… Well, we first showed that they came from local centers on the sun because the sun would chop off these local centers. And some of them came from above the... We’d receive some x-rays when the sun was totally eclipsed by the moon. Then we went to Point Arguello the next year and got some really good data in solar flares and particularly obtained the second measurements of energetic x-rays during the solar flares. But the first measurements really showed that the high-energy x-rays had more or less of a thermal [???]. This point is still argued about. And that they extended up to 120 or maybe even 200…120 kilovolts and that they really corresponded to these… these very hard initial x-rays corresponded to temperatures in the 100 to 200 million degree range. There’s a photograph of the old Asp rocket.

Hirsh:

You don’t [???] detector on it.

Chubb:

I’m looking, but I don’t think I have the main notebook for Aero-B 31. That’s the trouble.

Byram:

I might have the (?)etry available.

Chubb:

That might have it listed on what was there.

Byram:

Yes, if I can find that

Chubb:

That’s all down in the trailer. You could never get it right now. We have four detectors listed here which I think were ion chambers. I don’t know whether they were ion chambers or counters.

Byram:

Lyman alpha was ion chambers probably.

Chubb:

NL-ion, NL-ion, NL-[???], NL-counting (?). I guess we had both. So these must have been counters. I don’t think I have the main notebook here of Aero-B 31. (seems to be repeated and then there is a voice overlay again of apparently voices recorded backwards) More that’s repeated of what’s been transcribed above.

Byram:

There was an Aero-B 48. Do you know anything about it?

Chubb:

That was Churchill. The Aero-B 48 was Fort Churchill. I’d forgotten all about that.

Hirsh:

Where did you get the rockets?

Byram:

We bought them. We had the money to buy rockets in those days.

Hirsh:

Cooper Development Company?

Chubb:

We1l, we got the Aero-B’s and the Aero-jet; we got the Asp from the Cooper Development Corporation — that’s right. The Nike boosters we got from [???]. The Beacon — I don’t remember who we got the Beacon from.

Byram:

The [???] — I have no idea where they came from.

Chubb:

The balloons came from...

Byram:

The guy up in Minnesota?

Chubb:

Yes, the fellow down, went up on the [???] and fell down. He came from Lindsay.

Hirsh:

(?) leafing through papers. Not in this notebook. This I think is what I looked through before.

Chubb:

Did you check with our library?

Hirsh:

No. I called up Harmon over at [???].

Chubb:

What did he say?

Hirsh:

He said they were [???] Northrup [???]. (I’d) like to find out how NRL got involved in non- solar work. Obviously it was a side-product, a byproduct, whatever…

Chubb:

Well, once the navy clearly showed that there were x-rays from non-solar sources, we developed our thin window…We took advantage of our free flow gas techniques that we had worked out on the solar program and built large area counters. But actually the first one was a [???] wasn’t it? — with [???] free flow. This was a one with a beryllium window counter. That was the first post-[???].

Byram:

[???] beryllium window counter. It was an assembly of ion chambers, weren’t they? No, I guess they were [???]. I’m not sure.

Chubb:

I remember Julian Holmes helped B. Boyer get that thing ready at the very last moment. It was put into I guess one of our UV rockets.

Byram:

I don’t think that was the first one. It might be.

Hirsh:

But there was no consideration of non-solar x-ray sources before AS&E showed that there were some?

Byram:

I don’t think there were. (pause) Maybe you’re right, Dr. Chubb. There was a regular live rocket payload with two detectors, one of them built up by Boyer and Holmes. There was a bunch of very small beryllium window detectors all connected in parallel.

Hirsh:

And these were small angle detectors, weren’t they?

Byram:

There was a colorimeter out in front of them.

Hirsh:

And that had been developed previously for solar work?

Byram:

Well, it was similar. [???] stuff was always very small [???]. Solar intensities were so high that in general an aperture of 10,000 or even less would count.

Hirsh:

So is that how you could accurately determine where the source was?

Byram:

Yes. Well, that plus our experience in ultraviolet — we knew we could determine attitude of the rocket very easily; not easily, but we knew there wouldn’t be a problem other than the five or six weeks it took to solve the problem.

Hirsh:

But the NRL shot went up [???] rather quickly soon after AS&E.

Byram:

Yes.

Hirsh:

So if you only started planning that shot — when, in April ’53 (?) after you heard about AS & E.

Byram:

Yes.

Hirsh:

They only published I think in December ‘52. You must have had some contact with them beforehand.

Byram:

No, that’s about all the time it takes.

Hirsh:

You can do it that quickly.

Byram:

We may have had some word beforehand. I’m not sure. I’m sure that AS&E didn’t keep it secret.

Chubb:

This is our first publication and it does describe the relationship between us and the AS&E and then the Fisher-Meyer... Remember Fisher published something which was a bunch of junk…

Byram:

Did you talk to Fisher?

Hirsh:

Yes, I have.

Byram:

Where is he now?

Hirsh:

He’s at Rasor (?) Associates; no longer with Lockheed. The same area — the same [???].

Byram:

How about Acton? Did you talk to him?

Hirsh:

No.

Byram:

What was Acton’s first name?

Chubb:

Loren.

Byram:

Loren. He worked with Fisher.

Hirsh:

Oh, right. That’s his grad student, [???] student working with him.

Byram:

But Loren Acton worked for us also.

Chubb:

Apparently that first beryllium counter was a proportional counter because...

Byram:

I’m sure it was.

Chubb:

I’d forgotten that. It seemed to have four energy channels.

Byram:

I remember the four channel analyzer.

Chubb:

What was the date of the rocket firing that’s referred to there?

Hirsh:

April, ‘63.

Chubb:

I bet you that was one of those till Aero-B’s.

Byram:

I’m sure it was.

Chubb:

We had a beautiful Aero-B housing that we could put most anything in at that time.

Byram:

And I guess by that time the parachutes had started to work?

Chubb:

I believe so.

Byram:

So we fired the same frame over and over and over and that made preparation of a new payload very easy.

Byram:

It seems like compared to flying an experiment that’s in satellite, that these rocket shots would take practically no time to set up some of them. It’s obviously an advantage, although if you didn’t something up there all the time to see, for example, x-rays from the solar flare — Did either of you go to the Smithsonian astrophysical conference in 1960 on x-ray astronomy?

Byram:

In 1960?

Chubb:

I don’t think so.

Hirsh:

There were some discussions about what objects should be looked at for x-rays besides the sun. I think Dr. Friedman was there.

Chubb:

I’m sure that I didn’t go.

Byram:

And I’m sure I didn’t. There was a ultra-violet symposium that year that I went to, and I don’t think I went to anything else.

Hirsh:

Do you know if maybe Dr. Friedman had some preconceptions about what to look at besides the sun for x-rays?

Byram:

Oh, everybody did I think.

Chubb:

In those days, though, you didn’t look at anything. We didn’t have pointed experiments. You just sky mapped.

Byram:

We knew that there were certain things that were...

Chubb:

Of interest, like say nebulae. May 15, 1963. What was that? That was April.

Hirsh:

April 20, ‘63.

Chubb:

(still going through papers) Oh, this is all about the nebular shot.

Byram:

That was June (?) of ‘64? Or was it July of ‘64?

Chubb:

Yes. I need the notebook that comes before this.

Hirsh:

Did you have anything to do with NASA?

Byram:

Well, we lost a lot of people to NASA when NASA was formed.

Chubb:

Also, NASA supported the Holbert plan. Maybe that was a little later. I guess it started off as a…

Byram:

And got a center started here at NRL, because they used some of our buildings while they were waiting for their own buildings to be completed. So we shared a lot with them in those early days.

Chubb:

Two of our key men went to NASA. [???] went there and Kaperian. Actually, John Lindsay — Kaperian and Lindsay.

Byram:

But [???] worked with [???]. He did more for us than he did for [???].

Chubb:

We had a friendly conversation with him [???].

Byram:

… early experiments had scintillation detectors that might have had enough sensitivity to [???]

Chubb:

We did see, you know, in some of that solar flare study at Portabello (?)… The diffuse x-rays were seen on assimilation counters coming in from above. So we did have the [???] hacked (tracked) in to the diffuse x-ray background early. There was an Aero-B 49 fired in February of ‘62.

Byram:

That was an ultraviolet.

Chubb:

Yes.

Byram:

Do you think that may have had...?

Chubb:

Well, I’m wondering if I have a detector [???]. Remember those had those telescopes.

Byram:

Yes, that was the [???] first telescope, wasn’t it? No, we must have had one before that, but 48 seems like one of the first numbers.

Chubb:

April 19th, is that what that says?

Hirsh:

29th.

Chubb:

Oh, 29th. This must be that flight: MB 3.130. Here are some data. It has the channel listing: calcium fluoride, three telescopes, a magnetometer, three tube ray (I don’t know what that was), air glow 1, air glow 2. That may have been... telescope 4, 5, and 6, aspects.

Byram:

Wasn’t that ‘62?

Chubb:

19 tube ray. Now, what was that? That was a sum (?) of little proportional counters, wasn’t it?

Byram:

Yes.

Chubb:

I’d forgotten about that. 19 tube ray.

Byram:

I don’t know what the sweet (?) tube ray is. Is that a picture of the tail?

Chubb:

There’s the detector, the x-ray detector is described there. Now what about the 19 tube ray?

Byram:

[???], isn’t it? Didn’t he have an array of [???]?

Chubb:

Is that an array of detectors? Those were these amperax tubes, weren’t they? The end window...

Byram:

They were end window tubes. I know we had an array of those, but whether that was what Boyer had, I don’t remember. Did Boyer have that first?

Chubb:

That’s not the one Julian worked on I don’t think.

Byram:

I don’t know. I remember that I worked on one and Julian worked on one. And I don’t know whether the one I worked on operated [???].

Chubb:

Well, now this 3 tube ray says, “Pull tight (?) analyzer #1.” But it could be 3 [???] 9 tube ray. I’m not quite sure. I don’t know whether that says 3 or 39.

Byram:

39 sounds more like what Julian [???]

Chubb:

I didn’t remember that as being an array.

Byram:

It may have been a single detector with a bunch of [???] holes (?). I know it had a bunch of [???] holes (?).

Chubb:

That’s what it was. That’s right. It had whole bunch of all cylindrical end windows and a [???]. Is that 39? And the other was a collection of matched Amperex tubes, and there was a terrible time getting them all to have the same gain, which was a 19 and which was a 39? It probably doesn’t make any difference. Okay. Well, that shows that our April 23rd flight, whatever it is, was basically a UV astronomy experiment and it carried two large area proportional counter assemblies. One of them we’re pretty sure was made up of the collection of commercial end window proportional counters manufactured by Amperax and the other one was this multiple anim (?) detector with a common (?) window with all the anims (?) connected together. It was end window 2. Instead of wires going across, they were little studs. Okay. 30 tube ray. Here it is; 155 ca1ibrated by Boyer and Botsman (?) using rocket ray meters and output voltage readings, blow channel, the ion 55. The resolution wasn’t too sharp. In the lower channel we wanted 36% of the counts from ion 55 to appear in the low channel and we got 42. In the medium channel, which was set right at the ion line, we wanted 54%. We got 50%, and on the high channel we wanted 10% and we got 8%. That’s four days before launching. So what we did obviously was take our pre-plan UV rocket and add this assembly of detectors to get back into business and try to get started in x-ray astronomy as soon as we learned of the A S & E results. It was the next flight that we went to the large plastic window counters, which have become our bread and butter and really our [???] as far as x-ray astronomy goes. But these first ones were sealed off with no gas system, As I say, the real core of our effort at this period of time as far as night-time astronomy was to sort out really what was going on with all the early type stars and clearly this proves the fact that these very strong stars had nebular envelopes about then. And I don’t know whether you’re interested in any reports from that…

Hirsh:

Yes, I was going to ask you... When we talked on the telephone you said that there were theories that there were some hot plasma (?) nebulosities (nebulosity) around stars which made them emit mount-like point sources anymore.

Chubb:

This is the paper that Byram and I published on the UV data. I’m only down to my next to the last copy, so I think I’ll xerox it too for you. This has a discussion of the nebular glow not being there in this paper in the last paragraph. I’ll get a copy of that. This is the paper that turned out to be totally wrong. This is what we were trying to correct the record on. I don’t know whether that was the one that finally corrected the record, but the thrust on this paper is to really give our intensity measurements on stars.

Byram:

These was a paper strictly on the nonexistence of the [???].

Chubb:

Of the [???], right. I’ll see if I can find that. Here are (our?) star signals, you see, with [???] ion chambers cross the stars. You’re right. There was “The Nonexistence of the Nebular Glow” paper, something like that.

Byram:

Maybe George Carruthers published that.

Chubb:

No (?)

Byram:

Because I know he made angular measurements on our polometers that proved that what we saw was completely due to...

Chubb:

“On the Absence of Nebular Glow.” This is the one that put the record straight. That’s really after this. See, we really didn’t have an absolute proof until even later. You see, this one was ‘53. Finally we went right over [???], you see, and there’s no evidence of any glow around the background even though the [???] is tremendously saturated. So that was the proof really that there was no nebular glow.

Hirsh:

What did you think the glow meant before you found out that [???]

Chubb:

We noticed that none of the regular [???] in that original pater. It wasn’t really because we necessarily disagreed with the results entirely. It was just that we never really got much chance to work on the results of that paper, because they thought this was really exciting and super, which it would have been, of course. But then we tried to figure out what really was going on, and I don’t know if we even know (?) for absolute certainty or not; but certainly scattering in the colorimeter is still a good bet I think, don’t you?

Byram:

I think that… George showed that that colorimeter gave spurious responses at just exactly the right [???].

Chubb:

We had a lot of trouble also I remember with our little [???]. I think that’s what you’re thinking of.

Byram:

No, I’m thinking of the original nebular… I think George measured those original culminators, I know I still have them.

Hirsh:

Is that George Carruthers?

Byram:

Yes.

Hirsh:

But were there any follow-ups on this? I see Kaperian’s article, “Observational Astrophysics From Rockets — I, Nebular Photometry, 1300 [???].” But there are two, three, and four.

Byram:

He continued to make that claim, and I don’t know anything about his publications. He didn’t write anything more while he was at NRL that I know of, He went to NASA in the fall of 1958.

Hirsh:

If there had been a glow, what would that have indicated?

Chubb:

Well, it would have been very important. It would have indicated that...

Chubb:

... And Milliken was an astronomer, so there were two astronomers in the program early. Baggus (?) and Milliken were astronomers. And Baggus did his study at the University of Michigan, I believe, on H alpha, hydrogen alpha mappings, mapping nebular emissions. This would have meant... I guess that the stars were surrounded... that the stars, really were producing a lot more UV that was being absorbed and re-emitted by gas around the stars. It really would have said that there were huge quantities of UV emission from the stars or maybe particle emissions like giant solar winds, which do occur, but that these were being stored and reconverted to longer wavelength UV light at vast distances from the stars, and that really most of the interstellar medium then would have been in what we call H2 regions — ionized regions rather than neutral regions. In fact, I remember their talking about the possibility of our being inside the ionization shell produced by the star cycling (?). So it would have had major implications on the structure of the galaxy, so it was a very exciting thing to have. So they were right to realize its importance. It just turned out that there was some sort of instrumental problem that wasn’t obvious at the time. It did take several years to track down.

Byram:

I don’t know whether Baggus gave up before Kaperian or not, but I know Kaperian didn’t give up for a long, long time

Chubb:

But it was one of those things that it was really important to straighten out the record on, because really the UV stars go exactly as they’re supposed to go. Their point sources were just about the right emission. Now, our photometry seems to be lower than what people are getting now on the stars. I don’t know that we were too far off at 14.27 and 1304, but we were quite far off below [???] alpha. But some of those below lyman alpha counters were pretty marginal.

Hirsh:

Did you have anything to do with Project [???] in the Defense Department, AUC satellite? No one around here did?

Byram:

I don’t think so, Dr. Chubb may know about it. Was that where they launched a big rocket from Johnson Island?

Hirsh:

Well, it was a number of satellites that were sent up [???] nuclear explosion in the States. Apparently they have to put on a few x-ray detectors, and I was wondering if [???] (I?) had…

Chubb:

[???] see what they have. (from across room)

Byram:

Dr. Chubb may know about it.

Chubb:

We never published anything on that?

Byram:

No.

Hirsh:

This was Araby 32?

Byram:

I think so. This was an ultraviolet experiment (?). Let’s see: [???] first telescope experiment rather than just a colorimeter. Instead of a mechanical colomation we had actually a Newtonian telescope [???] [???]

Chubb:

We took these nebulosities seriously at that time because at the start of this program because we had something: Araby 31, Orion nebulosity, Araby 31, Virgo nebulosity, Lyman alpha night glow calculated for a 9-1/2 square degree detector. May 2nd, 1960 we have something: an astronomy rocket — at least we took data on it. We had calcium fluorodeno, flurodeno, lithium [???]; we had ... Oh, this is the dio(?) hydrogen, unsymmetrical, diethyl (?) hydrogen.

Byram:

Yes, that was the one below lyman alpha, wasn’t it?

Chubb:

No, that was the longer wavelength one.

Byram:

Oh, that was the 1500 [???] one.

Chubb:

... earlier ... our first astronomy rocket. (going through papers) ...whether this was strictly UV or not.

Byram:

We had an assimilation counter on one rocket but it didn’t work. I think (?) there was a high voltage problem.

Chubb:

(turning pages) [???] multiplier [???] volts, but I guess that was just an [???]. No, that was a secondary standard [???]. I still think those were great chambers we had in those days. This is the era of Corona regulators.

Byram:

There was a lot of education in those (?).

Chubb:

A Cronona (?), Orion calculation… Oh, the hydrogen filter experiments; four 6-inch Newtonians, eight 4-inch Newtonians. Remember we had that early experiment with the telescope coming out to the side before we had these...

Byram:

Yes, now we’re (I was?) trying to think of the number of that, too, but I don’t remember. It was with rockets on. It may have been 32. I think it was Araby 32 now that I think of it, and we scanned across Orion, and that telescope worked very well, though nobody ever paid any attention to the data. The aspect solution was good.

Chubb:

Yes, I think that was the lithium(?) l500 [???] And then we had the… The methalbromide (?) was the lyman alpha. I got the wrong formula down for the unsymmetrical [???]. No, I don’t either. The UDMH with methane in there [???] the electrical characteristics. X-rays. Ohh, look, at this [???]: calibration record of transmitter B and transmitter A. Here’s something called protime (?) counter 1 and protime counter 2, which I don’t know what they were.

Byram:

Well, they were an ion chamber.

Chubb:

I wonder if they were UV or x-ray, though. Time of moon [???].

Byram:

Yes, that was the one where we had the awful big aperture.

Chubb:

This is the one that had the 304 Angstrom photocell experiment. Remember that?

Byram:

Yes

Chubb:

With the magnetic shield that discovered the phenomena which has never been explored (?) exploded (?) yet.

Hirsh:

What’s that?

Chubb:

The discovery of meta-stable atoms and molecules in the atmosphere. We flew this thing which was really designed to be a UV detector that turned out to give a signal that was dependent upon whether it was looking up the rocket bypath or down — it wasn’t an external source. And it was apparently responding to excited species in the atmosphere that hit the photo surface and caused electrons to be ejected. And it’s probably an important method of studying properties in the upper atmosphere. It’s just never been picked up and pursued, but we do have a publication on it. So that was really the first attempt to look below 1050 Anstrom region in the UV — sort of between the x-rays and the... There is one source that has been detected in this region, and it’s called H-V 43, I think, which is a white dwarf, and I doubt if we could have seen that. No, we had an x-ray detector: x-ray result — spring firing: firing states count rate less than three counts per second most directions, less than ten counts per second; and then it says., “less (for counting rate of 10 counts per second we have 31.6 counts per second, and these were 50 Angstrom quanta. They correspond to 4.9 x 10/7 (erbs?) per square centimeter per second at 50 Angstroms…

Byram:

That must be the rocket where we saw the …

Chubb:

I don’t think we ever...

Byram:

Didn’t we have one rocket that was too close to sunset? We saw an awful lot of scattered sunlight?

Chubb:

I don’t know. I’m not sure which rocket this... Spring firing. What’s the spring firing?

Byram:

I don’t know.

Hirsh:

You’re wondering which rocket this is.

Chubb:

We don’t know yet. Sweeney was aboard. We had the Z detector. May, 1950.

Hirsh:

It was a night-time flight?

Chubb:

It might have been Araby 49 as distinct from B-2 49. It must have been May, 1960. That’s when all this is concerned with. So we were looking for stellar x-rays. We had two… We certainly had one, and then I guess when it says proton counter, that must have been an x-ray proton counter, because we certainly see results and you telephoned. You must have run that expedition and just called me up on the phone.

Hirsh:

And there were no...

Chubb:

Well, there were counts — 10 counts per second. Maybe we didn’t pick them up as x-rays stars, but maybe they were or maybe they weren’t.

Hirsh:

Was that background you picked up? You said there were some [???] counts.

Chubb:

Well, most directions, you see… No, it must have a localized source, because in most directions it was less than 3, but in some directions it was less than 10. So it must have been, you know, localized emissions. Here’s that 304 detector. We got a limit for a 304 of less than 120 for lyman alpha. There definitely was an x-ray detector flown in the spring, probably May of 1950, that did record counts, but for some reason or other we didn’t pick it up as x-ray stars, it was not Araby 31.

Hirsh:

Do you think anyone around here would have a list of all the rocket flights that [???]?

Chubb:

Probably, maybe Bob Aron.

Byram:

Well, somebody’s got to have an index of all those numbers. If it isn’t Aron, then Bruce Snyder ought to have them.

Hirsh:

NASA has only NASA flights, NASA-contracted flights.

Chubb:

I’m going to look and see if there’s anything... Remember we published those reports of the observatory [???]. I wonder if there’s anything in there. (long pause) There’s a report from March, ‘64 that talks about our positive [???] and also discusses nebular glow and stellar brightness. You can see those are the real of our program at that era. (pause) I think you ought to have a copy of this. It talks about the setting up of the Holbert Center and opportunities for people to come here and describes the program. This was in ‘63, you see. This was really an excellent program.

Hirsh:

What’s that?

Chubb:

This Holbert Center thing. Unfortunately support for it disappeared gradually… Here’s the way our group was set up at the time. This was the period of the solar radiation [???] satellites. Actually [???].

Hirsh:

The scientists who did the work here — did they all come from...? They were all stationed here. They all worked here. There was no contact work like from NASA. I know NASA let (?) a lot of contracts outside to universities and so on.

Chubb:

No, we don’t do contract work. Our contract work has always been strictly the responsibility of the Office of Naval Research, and we really haven’t even been allowed to contract for research, because that wasn’t our prerogative. It’s sort of different from AFCRL. Here’s what was said about stellar x-rays, [???].

Hirsh:

So you really, shifted gears from stellar x-ray ultra violet astronomy and so on after you heard the results of the AS & E group.

Chubb:

I would say so. But, of course, we had been in the x-ray business.

Hirsh:

Yes, you had the equipment.

Chubb:

And in a sense we did want to finish up this UV work, you know, too. And you can see how it… Now, in this publication, no mention of x-rays from the night sky.

Hirsh:

Which was this?

Chubb:

This is published in November of ’61.

Hirsh:

Oh, I see.

Chubb:

It did have this search for night helium glow it with an upper limit to the intensity. Now, maybe Friedman I think probably wrote the introduction. He might have said something.

Hirsh:

Did each group...

Chubb:

Each branch wrote down [???]. At this time for x-rays from the night sky, and we just didn’t consider this small signal sure enough to be meaningful, and the fact that it sort of is the first report from the rockets means that it’s something that we obviously were concerned with and wondered, you know, whether there was going to be something that showed up, but it also may mean that we missed an opportunity, because there was some signal that apparently was ... it may be — I don’t know whether it was — an x-ray star signal or not this time. And we were thinking in terms of longer wavelength x-rays rather than higher-energy x-rays because we interpreted it in terms of 50 Angstrom x-rays.

Hirsh:

This was that flight in 1960 or so.

Chubb:

Yes, we apparently had two x-ray detectors. That must be what those proton counters are. I want to find that page again. I really think I ought to look at the notebook before this one.

Byram:

I have one of your notebooks, but I don’t think it [???].[???] go down and see if I can find [???]. It might be somewhere I could get at it.

Chubb:

There are also apparently some January-February Arabys.

Hirsh:

1960.

Chubb:

1960, right. And the first UV mirror telescope was flown in 1959 — the rocket spectroscopy division with a single 5- inch telescope with a gascane ionization chamber. So you see that the way this thing worked [???] our exploratory experiments were often whenever there was an opportunity. But we certainly didn’t really know what to expect, and we were definitely in the mood just to look and see at that time; but clearly if we had imagined x-ray stars to exist the way they really do, we would have made a much more concerted effort than this and would have followed up things like this very small signal on x-rays; what seemed to us a very small signal on x-rays at the time. Of course ten counts per second is a healthy x-ray, you know, for a small detector.

Chubb:

Proton counter #1 and proton counter #2 were both on the north side of the rocket, (pause)[???] results on x-rays. That probably wasn’t an x-ray star — 31 counts per second per square centimeter: it’s really a count per square centimeter of 31. That would have to be Scorpios 6-1 [???] x-ray star. But this must have been a thin plastic window, [???] window, to give a 50 Angstrom sensitivity. And we considered it might be 10 Angstrom [???] also.

Hirsh:

So this is the energy at the source?

Chubb:

It’s the source, this ten counts per second — it’s sort of an upper limit really — but it imply that there was something in that direction. That would be the energy of it.

Hirsh:

If the source we’re emitting [???] 50 Angstroms?

Chubb:

Right, right. If it emitted purely 10 Angstroms, it wouldn’t be that value. Counter efficiency became 50% at eight Angstroms. I think I should try to find that notebook of 1959 because it probably has more of the planning on that. That was just after we did the flare studies. That may not be the [???]. The cosmic ray background shows count ray of 30 kilovolts which is much higher [???]. There was a discrepancy factor of 2 between two flights. This was dated ... it was obtained… I’m pretty sure this wasn’t published. It was obtained on the flare rockets. It shows the high-energy x-ray flare. [???] because it had been very exciting, you know, and no doubt that’s why they had this x-ray conference up there.

Hirsh:

Right.

Chubb:

So they were looking to find a way of breaking in, and they did very well. And then there was sort of competition between us and them. We didn’t want to get completely scooped and so we just… I mean it was also really exciting to try to catch up and restore what we thought was our leadership position and we did very well for a few years and then came along and they kind of wiped us out.

Hirsh:

And NASA came along.

Chubb:

I mean that really pre-empted x-ray rocket work to a great extent.

Hirsh:

Right.

Chubb:

And we moved on toward Heo.

Hirsh:

Which one day will go up.

Chubb:

[???]…I found something on the assimilation counter data and cosmic x-ray assimilation data from the… showing that the background was much higher than 30 kilovolts looking up than looking down at the earth. That was back in ’59. They seemed to have different rates on three [?] flights, which probably has something to do with [???]. Well, I guess I’m puffed (?) out.

Byram:

I am too pretty much. Besides I have a visitor coming in.

Hirsh:

I have this whole arrangement with the American Institute of Physics Center for History of Physics, and what they say is they will transcribe this tape for me if I get your permission to do that and also to deposit the tape with them. Is that okay?

Chubb:

Deposit the tape with them?

Hirsh:

Right.

Chubb:

I don’t know. What do you say?

Byram:

I don’t care. Nobody’s ever going to look at it.

Hirsh:

Well, you never know. What they’re trying to do up there is build up archives in the history of modern astrophysics and modern astronomy.

Chubb:

Well, I wouldn’t want anything I said to hurt any of the people who are still living, you know. That’s where I don’t mind them having the tape ultimately. I’d like to kind of control what comes out of these interviews a little bit. As I say, I don’t care what comes out ultimately, but I don’t want anybody to go over and listen to my comments and take those parts that they want to use when it might hurt somebody.

Hirsh:

Right, right

Chubb:

[???] people who are really my friends.

Hirsh:

Yes. Well, if they ever do make a transcript for me, I certainly can let you see a copy and you can do whatever you want to the transcript before it’s [???].

Chubb:

That would be all right. Well, are they going to keep a copy of the transcript, too?

Hirsh:

Yes. They’re very good with these things. They can put on stipulations, conditions, all that that the transcript cannot be seen until 1990 or something like that or whatever you want.

Chubb:

That will be fine.

Hirsh:

So they will make all these arrangements, all very legal and [???] and so on.

Chubb:

That would suit me very well.

Hirsh:

Okay.

Chubb:

It’s probably all right anyway. I might be able to be talked into some other arrangement, but I really would be a little more comfortable if we [???] I would say.